Today, we know that the role of vitamins and minerals goes way beyond the prevention of deficiency diseases (维生素缺乏症) to actually preventing cancer and heart disease, the most fearsome killers of our time. With this knowledge has come the widespread call for nutritional supplementation (营养补充) — and a confusing group of vitamin, mineral, and supplements lining the supermarket shelves.
Far from contributing to better health, however, nutritional supplements threaten to turn a scientific breakthrough into a nutritional disaster.
Promoters of vitamins and minerals — especially vitamins A, C, and E— would have consumers believe that the little vitamin pill in the bottle is all they need for good health. Take your vitamins in the morning, and you’re covered. It’s okay to eat fast foods for the rest of the day or skip meals to achieve today’s fashionably skinny look. But vitamins and minerals are only one part of the nutritional puzzle. A diet rich in fiber (纤维) and balanced in carbohydrates and protein is essential for good health. You can’t get these things from a nutritional supplement. The focus on vitamin and mineral supplements may actually be robbing us of the full nutrition we seek.
And no supplement can compare to the quality of nutrition found in natural sources. For example, our bodies turn carotenes (胡萝卜素) from plant foods into vitamin A. Many supplements contain a single carotene, but natural sources are rich in many different carotenes. Many supplements contain a form of vitamin E that is made from chemicals, when natural vitamin E is more readily absorbed and used by the body. And science is still discovering the wealth of nutrients in foods.
You’d be hard-pressed to find a supplement as nutritionally comprehensive and powerful as a balanced diet. Even if you could, you’d pay much more than if you got the same nutritional value from natural sources.
But perhaps the greatest danger presented by nutritional supplements comes from the very real risks presented by self-medication. Anyone can walk into the market and buy as many different supplements as desired. The reported benefits of high dosages of certain nutrients have led some people to believe that the more the better. Many take several vitamin and mineral supplements without regard to possible consequences.
Surprising new research suggests that vitamin C pills may speed up hardening of the arteries, the underlying cause of heart attacks. Researchers said their findings support the recommendations of health organizations, which urge people to avoid high doses of supplements and to get their nutrients from food instead.
As appealing as they’re made to sound, nutritional supplements are danger in disguise. If you’re looking for good health, don’t look on the supplement shelves of your supermarket. Look in the produce section instead.
1.What has given rise to the great need for nutritional supplements?
A. The knowledge of deficiency diseases.
B. The low prices of nutritional supplements.
C. The frighteningly high death rate from cancer and heart disease.
D. The information about the role of vitamins and minerals in health.
2.The “promoters” (Paragraph 3) most probably refers to ________.
A. businessmenB. doctorsC. scientistsD. fast food lovers
3.According to the passage, nutritional supplements ________.
A. are made from chemicals
B. are ineffective in supplying fiber
C. provide too much vitamin C
D. contain a kind of dangerous carotene
4.By describing nutritional supplements as “danger in disguise” in the last paragraph, the writer means that they are ________.
A. of little help
B. of poor quality
C. potentially harmful
D. extremely poisonous
One day, a teacher was speaking to a group of students about how to manage time. He gave such an interesting example that his students would never ________.
He put a wide-mouth jar on the table. Then he ________ some rocks and carefully placed them into the jar, one at a time. When ________ rocks would fit inside, he ________, “Is this jar full?”
Everyone in class shouted, “Yes.” “Really?” The teacher pulled out a bag of small stones. He put ________ small stones in and shook the jar. The small stones went ________ into the spaces between the big rocks. He then asked the group ________, “Is this jar full?”
“Probably not,” one of them answered. “Good!” the teacher replied. He brought out a box of sand and ________ some sand on the jar and it went between the rocks and small stones. Again he asked the ________ question, “Is this jar full?
“No,” the class shouted. Once more the teacher said, “Good.” He poured a cup of water into the jar ________ it was full. Then he asked, “What is the point here?” One student ________ his hand and said, “The point is that if you try really hard, you can ________ put more things in.”
“No,” the teacher replied, “that’s not the ________. What I want to tell you is that if you don’t put the big rocks in first, you will never get others in at all. ________ are the ‘big rocks’ in your life? Time with your friends, your education or your dreams? Remember to put the ________ in first, or you’ll never get others in at all.”
1.A. rememberB. likeC. forgetD. think
2.A. handed outB. took outC. carried awayD. put away
3.A. no moreB. not moreC. no manyD. not many
4.A. answeredB. readC. askedD. said
5.A. noB. fewC. anyD. some
6.A. upB. outC. downD. away
7.A. no moreB. once againC. a third timeD. a fourth time
8.A. sentB. putC. boughtD. collected
9.A. sameB. differentC. difficultD. common
10.A. sinceB. tillC. whileD. because
11.A. offeredB. placedC. raisedD. shook
12.A. alwaysB. alreadyC. neverD. hardly
13.A. pointB. exampleC. promiseD. story
14.A. WhenB. WhatC. WhoD. Why
15.A. sandB. small stonesC. big rocksD. water
The library needs ________, but it’ll have to wait until Sunday.
A. cleaningB. be cleaned
C. being cleanedD. to clean
If we are not ________ the progress we have made, we will have greater success.
A. interested inB. strict inC. popular withD. content with
At home, he keeps some pets,to which he ________ all his spare time.
A. spendsB. offersC. devotesD. provides
It is very ________ that she will ring me tonight.
A. likelyB. possiblyC. probablyD. perhaps